Railway traffic control and indication apparatus



J. M. PELIKAN 2,392,499

` RAILWAY TRAFFIC CONTROL AND INI-)ICATION API-ARATUS Jan." 8, 1946.

2 shets-shet 1 Filed ooms, 1943 v INVENTOR v t/n /K/)zz HIJ ATTORNEY m lll lll J. M. PELIKAN 2,392,499

RAILWAY TRAFFIC CONTROL AND TNDICATION APPARATUS Jan. 8, 1946.

2 Sheets-Sheet 2 Filed 00.1,. 9, 1945 v INVENTOR Jazz Waff/Falz lY/P ATTORNEY Patented Jan. s, 194e NI TED STATES l()fF.-F'I"Cl1 :2,392,499 nAmwAYimnFFlc'coN'rnoLnND INDICATION APPARATUS John.:M. zBelikan, hicago, 1111,., :a'SSiglwr to The gUnion .Switch & 'Signal zompany, rSwissvale,

APag, ,al corporationeof Pennsylvania Application Gctober 9, 1943, Serial No. 505,681

My invention Vrelates to ,railway tralllc control Aand indication apparatus, and ,particularly to apparatus for .,eiiecting Acontinuous control of a railway traffic governing device,` such fior eX- ample 4as a switch or a signal, over a `givenpair .5

of yconducto-rs, andatthe same time .effecting continuous control of indication apparatus over the same pair of conductors in the opposite .direction.

:Various schemes'have been devised ,for controlling arailwaytrack switch or 1a. signaljfromaremote control pointcver a `given pairoi line conductors, and for controlling indication means .at the control point over the same pair of line conductorsirom a Iieldlocation adjacent ,the switch or signal. In some of those schemes, ,constant current is used ,for'boththe control and Sindication circuits, so that only cneofsuchcircuits can. vbe closed at any given Vtime', and `hence ,thejinditrack Y *with a mainztrackX. Incrder-to simplify fthe drawings, 'each :of A1tljir-:se tracks Vis representedhy lbut a single line. 'These tracks are divided by insulatedjoints,designated by `the refercurrent, such for example as Va `battery 4, con- -of the section.

Traffic movements over switch I toward the right, as shown in fthedrawings, which 1-shall -as- -sumeis Ythe eastbound direction, are governed by signals designated by the `reference characters cation means cannot be controlled at the .same r1-R'A"'M1fl IRRW-llcrrswith l `lsinthe normal p0- :time as the `traiiic governing device is being controlled. "In other such schemes, anindication control 'relayis included, atlthe control point, in a given circuit in series with a control relay at 4the-field location, and -the A,circuit :is periodically interrupted at thee'ld 'location to control the/:indication 'relay 'at the control point. In still other schemes, `rcoded control current .is supplied "over a ,pair of conductors for 'eiecting energizasition or reverse position respectively, and traffic movements in the Opposite or westbound direction uover switch `I are governedlby signals ZLAand 2LB. Thesevsignals may be of any suitable de- .25 vsign-such, `for-example, as the searchlight type.

"The-contacts operated-by the various relays and other control devicesare identied "by numbers, -each 'such number having a distinguishing preliix.fromzwhich itis separated Iby a dash when the tion of d-a 4stick relay which `thenremans ener- -30 eaSSOCatedzcontactfis shown apart `from therelay ggized by a 'stick circuit while coded .indication current is lsupplied tothe same 'pair of `conductors.

'One feature of -myinvention is the provision of means for supplying successive Ipulses ,of current F01' D@m3119165 COlll'faCt-ZRiH--5'L ShOWIln 'Fgla at different 4frequencies and polarities at aeld location vadjacent a railway 'traffic governing device, such for example asa switch or a signaL'to agiven pair of conductors for effecting ycontinu- `orother `device 'bywhich it'isoperated. The prex for Leach ci :these contact `nummers comprises :thereference character for the relay or other device by which the associated contact is operated.

in the operating circuit yfor signal '2RA, is identil-eclinrthe number -5I which issepara-ted b-y a dashfrom theprefix `ZlfI-I which is the reference Achafrmter for relay Z'RH Aby which this .contact is ous-control voi indication means at :a remote-con- "40 Qperated,

trol point, and for supplying other 'pulses yof current of dilerent polarities to :thejsame pair of y conductors at fthe control 'point, during 'the :oi

periods between the successive pulses of-current supplied atfthe eldlocation, foreecting 'contin- 45 .Switch '.I "is operated .toits normal position, in which itis shown .in the drawings, ,orto the opposite or ,reverse .position `by Aa mechanism desig- .fnated bythe referencecharacter IW. Mechanism .IW is in =turn,control'1edhy.a polarized ,switch con- :ftrol `relay LW-R.

,-Afswitch contact 15 operated :in conjunction ,with switch 1I eso as .to.;be;closed .'for completing a `The accompanying drawings, comprising Figs. .50 QT energizing 2f normal S-Wh repeater la, 1b, 1c and 1d, constitute a diagrammatic'view showing one form vof apparatus Vembodying -my including'a switch lI `whichconnects an auxiliary .'55 Signals ILA-and QRAare lshown controlled .in 4

`relay IN Awhenfsvvitch II is `vin the normal position, and to be closed `forcomp'leting ya circuit forenerg-izing a reverse switch repeater :relay nIR when switch I -in its .reverse'position v periods. l

1f contact I4 of relayZPS or contact I3 ofY 2 Y o l 2,399,499

or relay 2HP`releases its contact I4 or I3, re-V part by signal home relays 2LH and ZRH, respectvely.

Referring'next to Fig. 1b, signal indication and approach indication control apparatus at a, remote control point, shown in the right-hand portion of the drawing, are controlled, over apair of conductorsr comprising a line wire I IV and ground designated GD, by successive pulses of current of normal or reverse polarity supplied to the pair' of conductors at various frequencies at a field location adjacent the switch and signals shown spectively, in the manner referred to in lines 40 to 56 inclusive, column 2, page 2 of the Blosser Reissue patent referred to. Contact 2P-I2 will therefore be closed at its front point for a brief period of time during each off period while the back point of contact 8 of ycode transmitter 'I5CT or vthe back point of `a similar contact of code in Fig. la. The various currents'suppliedto theA pair of conductors at the field location are provided from a source such, forexample, as a battery QI having a positive terminal FB, a, negative terminal FN, andV a center tap connectedtol ground GD. Y

If the signals are controlledsto indicate stop,V indication relays shown in Fig. llc, designated by the reference characters 2 RP and 2LP, are energiz'ed, andthe currentsupplied to conductors I I and GD is of normal polarity, whereas if either of these relays is deen'ergized, the current suppliedto 'conductors 'I'I anfdjGD isof 1re-:iverse Dolarity. f

'such @tirent ffl'gitrier ,pgiar'ity periodically interrupted by codetransnjiitters designated by the reference characters CT, I20CT, IBUCT and I'MBCT, respectively, 'to produce w75, 12,0, 180V or 240 pulses of currentY per` minuter according to th@ .energized 0f deenegzd CODOIO track relays V2L and 2R. Each of the code transmitters is connectedfacross the positive terminalB and o the centertap O of a battery Q2, and is therefore Y .Constantlvin operation, 1 1..

Current of either polarityand of any of the four frequencies mentioned is transmitted from the field location over conductors II vand GD throughthe back pointof Ya contact 2P,-I2 and `the windings of polar biasedcode following inrelay v2HE will Operate its Contact I3 in response @Death pulsa;

v .n slow releasesignal indication ,relayZPR' becomes periodically energized when relayY ZPS operates lits contact i4.; Because of its'slowreleasing characteristic, yrelay VZPR. retains its .contacts closed at their front points during the open cir.- cuit vintervals between the periodic energization relayZHP is beingoperated in response to successive pulses of current having frequencies of 120,118() or 240 per minute, one of three decoding relays, designated bythe reference characters V2LD, ZRD and 2LRD, respectively, will be enerthe primary' winding of a transformer ERF These decoding relays are selectively energized throughv resonant decoding units, designated 'by the reference characters' I20DU,` `IIlIlDU and 240DU, respectively, according to the frequency of the pulses of current by which relays ZPS and ZHP are energized, similarly to the manner referred to on page 8, columnl, lines 34 to 37 of Reissue Patent 21,783 granted April 29, 1941, to Herman G. Blosser for VApproach control apparatus for railwayv signaling systems. s Y

Axpol-ar biased'code following impulse relay 2P willoperateits contact '2P-l2 inwresponse to pulses'of current produced inthe secondarywinding I 9 of transformer 2R15' each time relay ZPS transmitters I29CT, IilCT and 24IJCT, respectively, is closed between the successive pulses of current supplied through the front points of the corresponding code transmitter contact.

Current pulses Vof positive or negative polarity according as aswitch control lever IV, shown in Fig. 1'd,is in its n or 1' position, will be supplied through the front point of contact 2P-I2 from a suitable source of current such, for example, as a battery Q3. The pulses of current supplied through the front point of contact 2P-I2 will bel transmitted over conductor Ii and ground GD and the back point of contact 8 of code transmitter 'I5CT or a back point of one of the similar code'transmitters IZGCT, ICT andrZllIlCT, accordin'gto the'condition of relays 2L and 2R, throughv the windings of polar biased normal and reverse switch control relays I NW and IRW, respectively, which may or may not be of the code following type. If these pulses of current are of normal polarity, relay INW will close its contact 23, whereas if the pulses of current are of reverse polarity, relay IRW will close its contact 42.

If a switch locking relay ILR is energized, relay IWRv will be energized `by currenty of normal or,

reverse polarity according to whetherv contact 23 of relay INW or contact 42 of relay IRW is closed. Switch locking relay ILR is inturn controlled by 'contactV ITE-22 and by Contact 2| of -an apswitch section indication control apparatus at the remote control point, shownl in the right-hand portion of the drawings, are controlled, similarly tothe indication control apparatus referred to in Fig. 1b, overa pair of conductors comprising a y line wire-'29`and ground GD, by successive pulses of current of normal or reverse polarity supplied mal polarity, whereas if" switch I is in the reverse Y position, so that the reverse switchrepeater relay Y IR is energized, the current supplied'tothefconductors will be of reverse polarity. The current of either polarity is periodically interrupted lby ,code ,transmitterV 'I5C'l, I 20CT `or I SCT to .pro-

duce 75, or 180 pulses per minute, respectively,`

according to the energized or deenergized condi'- tion of switch locking relay ILR and track relay Polar biased code following indication. relays INP and IRP, slow release normal and reverse switch indication relays, INR and IRR,trans former IRF, polar biasedcode following-impulse relay IP, and decoding relays ILD and ITDY are niece-,nee

controlled similarly to zthe corresponding aparts shown fEg. 1b. Polar .biased signal icontrol relays ZLR and ZRR are also controlled loy'afsgv-nal rcontrol ,lever .ZVsi'milarly lto vthe fmanner in @which `switch :control :relays INW and Y lRW are controlled by switchucontrol lever IVpas ydescribed in connection with Eig. lb.

ASignal-home Vrelays ,2LH andZRH are controlled .by `relays LZLRand ZRR, respectively. :Signal stop indicationzrelays 2LP :and :ZRP vare controlled lby circuits including .back .contacts .of relays 2LH and AZRH, respectively. .Referringstolfig ,-ld, a .trackimodeland"indication lamps are .herenhcwmttogether with switch control lever i V having :a :normal r position lu and Va :reverse :position r, signal control ylever :Zlhaviing :a :normal '.positionfn yand :control spositions f and r, and circuits tor controlling @the `indication lamps.

vHaving described, in lgeneraLithe .arrangement and control of the apparatus ishownibyltheaccompanying drawings, IV shall now describe, in detail, a few :typical examplesiof` its operation.

As .shown by zthecdrawings, all partsare "in the :normal condition, that is, `switch I 'is .in its normal position; .all signals are indicating stop; ftrack sections ZRT, IT: and 2LT are unoccupied, and hence the track relays are energized; :levers -IV v:and ZV .are vin .ths normal lposition n; .code transmitters JItlCT, IZBCT, |8.0CT land ZEUCT are energized, so they are constantly operating; relays ZPS and INP areoperating their contacts in responseto pulses of current of normal polarity from the `field'location; impulse -relays IP and ZP are operating their contacts; relay INW is periodically energized; relays IN, ZAS, ILR, iZPR, QZLP, fZRP and INR are energized; -relay y.HNR is -energized byvcurrent of norma-l polarity; relays itR, ZLD,ZRD, ZLRD, ZLR, ZRR, IRR, 2LH, iZRH,

ILD `and `ITD are deenergized; indication lamps `IINK and V2PK are lighted; and other indication 4lamps are deenergized,

The circuit by which relay ZPS is energized passes from terminalF'B of battery QI, through the front points of contacts 2RP-6, 2LP- 1, contact 8 of code transmitter'lCT, contacts vZl.f9 and ZR-I0, fconductor -I I, back point of contact V2P-I'Z, 'windings of relays YZPS and ZHP, and ground'GDback to the center tapof batteryQl. Relay ZPS is therefore `closing its contact I4 alternately at ythe Vfront and back points 'in re- -sponse'topulses of current, having a frequency of 75 per minute, flowing in this circuit.

-Relay ZPR is periodically energized through a Acircuit including the iront pointof contact I4 of relay ZPS, this circuit passing from terminal OB of a suitablesource of current, such for-example as battery Q3, through the backpoint of contact I3 fofzrelay 2HE', front'point of contact .I4 of relay ZPS, Winding Aof ,relay 4ZPR, portion 1I 6 of .the primary Winding oftransformer ZRR and .ground GD'to'the Vcenter tap of battery Q3.

In response to the periodic closing of contact |14 l'of relay Z-PSat its back point, relay 2P operates its contact ,ZP-I2 in the manner referred to in the Blosser reissue patent.

Each time contact ZP-IZ closes at its front .p oint, a'circuit is completed for `,energizing relay INW, .this circuit passing from terminal OB of battery Q3, through -contact IV-ZIJ 1in the lefthandposition, 'frontpoint of contact @ZP-I2, conductor 'I I., front points of contacts ZR-I and `"2L-19, back point of` contact 8 of code 'transmitter 15CT, the windings of relays yllt-W and INW, Yand ground sGD rtothe vcenter-tap of `battery Q3.

Switch :locking relay lsR:is. energi-zedehy,afcir cuit including f'contact .lf2-1 of :relay :2 `.contact VIR-112, andithewindingjofrrelay ILR-to'terminal-;0. l

.Polarized .switch control :relay .,IWR is there- `fore .energized by nur-rent :of :normal polarity a ycircuit ipassingzfrom terminal 5B of battery LQZ, zcontactZ'S sof .relay INM/, contactlZA of. relay Land 4the winding lof relay IWR fto terminal 'O'.of :batteTyQl Y fWith relay '.'YIN energized,` on account of .switch ;`=I lacing `-its :mormal zposition, a circuit `is Acompleted, asfshown in Eig. fic, '.for energizing relays yINP .fand yJRPlfby current -of normal .polari-ty :to which relay atNP .responds by .operating its con- Atact 532, this icircuit passing A.from :terminal FB, :through :the front :.points :of #contacts IIN-25, 'HCT- 16, IIR-.21 aand :EDR-128, .conductor 29, back `point tof .contact IR-130, and `windings vof relays ,and l I RP,.and-ground GDuback to bat -tery Qf| ;Relay `INR lwill :be periodically ener- .fgized ,doy .current passing lrom 1terrninal1.OB, through athe aback --pont .of :contact .34 -of relay iIRP., ifrontzpointlofhontact' Zf-.of relay V=l NP, .wind- -nggof relay I NR, ;por\tion33.-of the primary winding of transformer ilfRF, .and ground `GD back Vto .battery -;Q3. Impulse. .relay :IP is now periodically venergized in'response tto :the periodic closing -of contactez vof relay INPat its backvpoint. Relay .IP therefore roperates its contact IP`30 alter- '.natelyxhetween the .iront and back fpoints.

'With llever `:ZV :occupying Lits normal position, the teircuits including the front Ipoint of contact :IP- for .energizing relays vZLR vand ZRR are open, :and :hence .neither of these relays `is ener-- igized. With slow :release :relay 1NR energized, la circuit is completed #for constantly lighting iin- -dication lamp `l NK, this `circuit, passing fromfter- 'minal'B'of alsuitablelsource of current, through contact 1NR-'311,and lamp INK vtoterminal O ofthe same sourceof current. With relay ZPR energized, an findicationcircuit -is completed for #energizing lamp LZPK, lpassing :from terminal B, 'through-the front point offcontact 2PR-38, and

Ii shall assume that, vwith all-parts ,thus in vthe normal condition, yan eastbound `train arrives on section ZRT, :deenergizing relay ZR. The circuit 'previously' traced through contact 8 of code transmitter "ISCT Afor energizing relay ZPS will now be opened lat the yfront'point of contact ZR-'IS0, and a second circuitwill be completed, 'for venergizing relay ZPS, which is the same as 4-the vcir- 'cu'itfpreviousl-y traced as far v'as the vliront ypoint yof Lcontact 2LP- 1, and-then passes through the front point of Icontact 39 of transmitter IBUCT, front point `of contact-2h40, :and vthe back point of contact ZR-Iffand-is then the sameas the vcircuit previously ftraced. f-Relay `ZPS will nQw respond to current of ypulses per vminute and impulse relay lZP will `-now operate its contact fZP-IZ 180 times `per minute.

tDecoding relay ZRD `Will now be energized rthroughthe decoding unit I80DU in response to theipulses of current havinga frequency of 180 per minute. With Ire'layZRD energized, a circuit vWill be completed forenergizing indication lamp 'ZRK in the `track model, this circuit L'passing from yterminal `B, through'contact `2RD-4I, and lamp ZR-Kto terminal O.

LRelay vINW will now respond-'to current of 180 ypulses yper 4minute in acircuit which lis the ysame asi-thecircuit previously traced for Vvthis relayas ufar yas conductor '-Ifl, Yand Athen passes lthrough 'the "back point o'f contact V'ZR-"Ill, -front--po1nt voffcontactY 2L-,V-40, back point ofcontact 39 of transmitter '.I 80 CT; and then' through the windings of relays IRW and INW toground GD.

I shall further assume that the leverman 'now desiresto reverse switch I. Hewill, therefore, move lever IV to the right-hand position, thereby completing a circuit :forv energizing relays IRW and INWV'by current of reverse polarity to which only relay'rIRW responds, this circuit passing from the center tap of battery Q3, through `ground GD, the windings of relays INW and IRW, back pointv of contact 39 of transmitter I80CT, Vfront point of contact A2L--4Il, ,backY point of contact 2R,-- II), conductor LII, Yfront point of contact 2P-I2, vand contact IV-f-Z Vin the right-hand position totermnal ONVof battery Q3. Relay' IWR .will now becomeenergized by current Yof reverse polarity passing from terminal O of bat-A tery'QZ, through the'winding of relay IWR, con-v 4tact 24 of relayILR, 'and contact 42 of relay vIRW to terminal N of, batteryQZ. With relay IWR en-V 4 ergized by current of reverse polarity, mechanism 'IW` will be energized for operating switch I to the reverse vposition by a circuit including contact IWR-43, contact ,IWR+44 closed in the righthand position, and mechanism IW to terminal O.

Upon the operationof switch I to the reverse position, ,contact 5 will become closed in its reverse position-,causing relay IR to vbecome energized bywa vcirc-uit Apassing from terminal B,

through contact 5 in ther'everse position, and

ing traiic past signal 2RA, this circuit including contact 2RH-5I, and VtheJmechanism of signal 2RA to terminal O. i

With relay ZRP deenergized, acircuit fWill be periodically closed for energizing relays 2PS and 2HP by current of reverse polarity to which only relay 2HP will respond, this circuit passing from battery QI, through ground GD, windings of relays 2HP and ZPS, back point of contact 2Pv-I2, conductor II, front points of contacts 2R-II) and 2li-9, front point of contact 8 of code trans'- mitter 15CT, front point of contact 2LP-1, and the back point of contact 2RP-6 to terminal FN. With relay ZPS constantlyrdeenergized, itsv contact I4 will be constantly closed at the back point and hence relay ZPR will be'deenergizedcaus. ing indication lamp ZVRK to become energized by -a circuit passing from terminal B, through the back point of contact 2PR-38, contact 50 of lever 2V closed in the r position, and indication lamp VRK to terminal O.

winding of relay IR to terminal O. Relays lI RP and INP, shown in Eig. 1c, will now become energized by current of reverse polarity to which` 1 only relay I-RP -will respond, this circuit passing i from the center tapv of battery QI, through ground GD, `the windings of relays IRP and INP,

back point of contactAIP-3Il,V conductor 29, front Y v points of contacts YITE-28, ILR-Z'I and ISCT- i 29, and contact IR- to terminal FN. Contact 3,2 of relay INP,V will therefore now be con,-

, stantly closed at its back point, and contactr'SI of relay IRP ,will4 be valternately closed at its front and back points. Relay IRR will therefore now be energized by a circuit passing from terminal OB, through the front point of contact I3I of relay RRWinding of` relay IRR,'and portion 33 0f the Vprimary winding of`Y transformer IRF to ground GD; Withrelay IRR thus'energized, a

circuit will Ybe completed for `energizing indigcation lampr IRK, passing from terminal B, 1 throughcontact IRR-46, and lamp AIRK to ter- ,minalOtz N I shall now assume that all parts of the ap I paratus are againin the normal condition, and @that the leverman decidesv to clear signal 2RA. He will, therefore, move lever 2V to therighthand position, vthereby completing 4a circuit for energizing relays ZRR and ViLR bypcurrent of reverse ypolarity `to which only relay ZRR responds, thisA circuit passing .from the center Vtap of battery Q3, through ground GD, the windings lof relays 2RR and 2 LR, :back point of'Ycontact HCT-26, front points of contacts ILR-ZI and lTR-28, conductorY 29, frontv point of contact IP-Si, and contact 2V-4I Yclosed Vin the right- `hand position, Vto terminal QN.,- Withrelay ZRR thus energized, signal home relay 2RHwil1 be energized'loy a circuit passing fromterminal B,

`through'contact 48 of relay 2BR-and the winding of relay ZRH toterminalO.V Signal stop in- `dication relay 2RP will therefore rbe `deenergizedV because ofY theY openingfof Contact 49 oflrelay 2R11V YWith relay ZRH energized'the arm of signal 2BA will; be Operated iosa `positionindirect.-

From the foregoing description and the accompanying drawings, it follows that in apparatraic condition such, for example, kas the posiy tion of a switch, the indication displayed by Va signal, or the condition of a track relay or of a switch locking relay, can lbe continuously controlled by successive pulses of current 'supplied to a pair of conductors such, for example, as a line wire and ground, while at the same time a switch or a signal can be continuously controlled from the remote control station by other pulses of current supplied to the conductors between the successive pulses of indication current.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that Various changes and modifications may be made therein within the scope of the .appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In control and indication means including a pair of conductors and means for supplying successive pulses of current to said conductors of each polarity at each of a plurality of frequencies one for each of a corresponding plurality of traffic conditions, including a normal code following relay and a reverse code following relay responsive to said pulses of current of normal and reverse polarity respectively, the combination comprising, a contact of said normal codefollowing relay and a contact of said reverse code following relay each having afront and a back point, a reverse indication circuit including the front point of said con-V tact of said reverse code following relay, a normal indication circuit including the back point of said contact of said reverse code following relay in series with the front point of said contact of said normal code following relay, normal and rev'erse indication'means controlled by said normal indication means selectively controlled by said front contact points according to the frequency of said pulses Vof current but independently of the polarity of said pulses, a third code following relay,

a circuit including said back points rof said contacts in series for energizing said third code following Vrelay, and manuallyV controllable circuit4 means including a front Ycontact of said third code following-relay. and including said pair of conducescaneo polarity respectively, the. combina-tion comprising, v

indication means` selectively controlled.` by front. contacts` ofsaidy code following; relays according totheipolarityandfrequency ofthe pulses of our` rent 'by which` said:I codeffollowin'g relays are energized, a: third, code following relay,., means-controlled byv back contacts. of, said normal andre.- verses. code following; relays irl-series for effecting. operation 1 of said. third code following., relay during they oif periods.x between-:saidi successive pulses of current and manually controllablek circuit means-including a-front contactof saidz third' code following relay andgincludingsaidpair of conductorsffor: selectively? effecting. opera-tion'y of given trafficzgoverningmeans'. y

3; In. control-,and indication meansv including: a pain of conductors; the; combina-tion comprising, means for supplying successive pulses' of current of. said frequencies? according to one or; another traiiic ,governing condition, normal. and reverse code following relays' responsive; to saidpulses of currenty of. normal and reverse, polaritlesr indication'` means,v selectively controlled by said code following relays accordingtothexfrequency of the current-pulses but independently ofth'epolarity of said pulses, other indication means selectively controlled by fr-ontcontacts ofy said codefofllow-t ing relays :according to'-r the polarity of said. pulses ofV current, and manually` controllable: circuit means controlledby back contacts of said code fol-lowing relays for supplying otherpulsesoffcurrent-to-saidI conductors duringgt-heoff periods betweensaid, successive pulses oiicurrent ofY each. frequency of said pluralityl of frequenciesl for effecting; operation of given. traflic governing means.

6; In. indication means-:fora signal;4 and control t meansrf or a railway track switch, including a normal.` codeA following, relay= andra reversecode fol'-` to; saidrV conductors at each; of a; plurality ofV frequencies one: for.' each; cfa plurality ofv traffic conditionsiand ofnormalV or,-reverse-` polarity at each of' said frequencies accordingto one, or` another traffic. governing condi-tion;` a normal and a. reverse` codez following` relay;` selectively responsive tof saidfL pulsesy of current of normal and reversepolaritiesrespectively, indication nieansiselectivelyrcontrolled by said code following relays according to the frequency of the currentpulses by whicntl'ieyarelenergized but independently of the polarity of said pulses, other indication means selectively controlled by said code following relays according to the polarity of said pulses of current, and manually controllable circuit means controlled by said code following relays for supplying other pulses of current to said conductors during the off periods between said successive pulses of current of said plurality of frequencies for effecting operation of given traiiic governing means.

4. In control and indication means including a pair of conductors, the combination comprising, means for supplying successive pulses of current to said conductors at each of a plurality of frequencies one for each of a plurality of traffic conditions and of normal or reverse polarity at each of said frequencies according to one or another traiiic governing condition, a normal and a reverse code following relay selectively responsive to said pulses of current of normal and reverse polarity respectively, a contact of said normal code following relay and a contact of said reverse code following relay each having a front and a back point, indication means selectively controlled by said contacts according to the frequency and polarity of said pulses of current, and manually controllable circuit means controlled Iby said back points of said contacts for supplying other pulses of current to said conductors during the off periods between said successive pulses of current for effecting operation of given traffic governing apparatus.

5. In control and indication means including a pair of conductors, the combination comprising, means for supplying successive pulses of current to said conductors at each of a plurality of frequencies one for each of a plurality of traffic conditions and of normal or reverse polarity at each lowingrelay andatpair of conductors, the combi.-y nation` comprising,v means; for-:supplying successive pulsesf'of. currentv to said conductors of norma-ll or reverse` polarity according f asiI said: signalV4 displays a first or asecond,indication;respectively for energizing said code following' rela-ys',J indi-cation means controlled by front, conta-cts of. said code following. relays to display a rst or; a,` secondiindication according as said. pulses ofi current, areV of normal or reverse polarity respectively,1a-man.` ua'lly operable? device, means; controlled bysaid manually operable device .and .by back'contacts; of said coder following relays for supplying; other pulses. of current, of nonnaltor: reverse polarity/to said'. conductors duringvtherv offv periods'. between said: first pulsesof current; and: means controlled by other pulsesfof; current of normali or: reverse' polarity fon operating; said switch toiitsi normal or its reverse position respectively.

. '7. In indication means for a signal and for a plurality of other traic control devices and in control means for a railway track switch, including a normal code following relay and a reverse code following relay and a pair of conductors, the combination comprising, means for supplying successive pulses of current to said conductors of normal or reverse polarity according as said signal displays a rst or a secondindication respectively and at one of a plurality of frequencies each of which is provided only in response to a given set of conditions of said other control devices for energizing said code following relays, indication means for said other trafc control devices selectively controlled by said code following relays according to the frequency of said pulses but independently of the polarity of said pulses, indication means for said signal selectively controlled by said code following relays according to the polarity of said pulses of current, a' manually operable device, means controlled by said manually operable device and by said code following relays for supplying other pulses of current of normal or reverse polarity to said conductors during the off periods between said first pulses of current, and means controlled by said other pulses of current of normal or reverse polarity for operating said switch to its normal or its reverse position respectively.

8. In indication means for a railway track switch and control means for a signal, including a normal code following relay and a reverse code following relay and a pair of conductors, the combination comprising, means for supplying succes,- sive pulses of current to said conductors of normal or reverse polarity according as said switch is in its normal or its reverse position for ener` and `a back point, indication means controlledv by the front points lof said contactsrof said code following relays to display a 'normal or a reverse indication according as said pulses are of normal or reverse polarity respectively, a manually operable device, means controlled by said manually operable device and by the back points of said contacts of said Ycode following relays in series for supplying other pulses of current toV said conductors during the off periods between said first pulses of current of one polarity, and means controlled by said other pulses of current forV clearing said sig-nal. Y

9. In indication means for a railwayftrack switch and for a plurality ofother control devices and in control means for a" signal, including a normal code following relay and a reverse code following relay'and a pair of conductors, the comloination comprising, means for supplying successive pulses of current to said conductors of normal or reverse polarity according as said switch is in its normal or its reverse'position'and at one of a Y plurality'of frequencies each of which is provided only in response to a corresponding set of conditions of said other control devices for energizing said code following relays, a contact ofsaid nor-V Vmal code following relay'and a contact of said reverse code following relay Veach having a front and l a back point, indication' means selectively conl ity of said pulses of current, manually operable means, means controlled by said manually operable means and by the back points of said contacts of said code following relays in series for supplying other pulses of current to saidrconductors during the olf periods between said first pulses of current of one polarity, and means con# trolled by said other pulses of current for clearing saidsignal. Y. Y

10. In indication means for a plurality of control devices and in control means for another control device, including a normal code following` relay and a reverse code following relay andv a pair of conductors, the combination comprising, means forrsupplying successiveV pulses of current to said conductors of` normal or reverse polarity according as there exists one or another set; of conditions of said plurality of control devices and for supplying said pulses at any one of a plurality of frequencies according as there exists a corresponding other set of conditions of a correspond ing plurality of sets of conditions of said plurality of control devices for energizing said relays, a contact of said normal code following relay and a contact of said reverse code following relay each having a front and a back point, indication means selectively controlled by the front points of said contacts of saidlcode following relays according to the frequency and polarity of said pulses, Inanperiods between said first pulses of current, andy means controlledvby'said other pulses of current for energizing said control means forsaid another control device; Y l

' nJOHN M. PELIKAN.

CERTIFICATE OE CORRECTION. Patent No..A 2,592,}.L99. l January 8, 19lp6.

' JOHN N. PELIKAN.

It is hereb;r VCertified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 6,Y fvirst Column, line 56, claim 9, for "means" read --relays--g line 5'( ,Y same claim,

for re1ays read --means; and that the said Letters Patent should be read with this correction therein that the same may conform tol the record of the case In the Patent Office. o

Signed and sealed this 26th day of March, A. D. 1914.6.

Leslie Frazer' Y (Seal) First Assistant Commissioner of Patents. 

